Fake period??

Marija

I got my period on Monday,not Tuesday like I'm supposed to and had sex two times in four days having it.Every time a day after sex period was quite light and on 4th day it stopped.Trought all these 4 days I've been feeling strange,had headaches,nousea and pain under my breasts so hard that I came home from work.I bought a pregnancy test and I want to try it tomorrow morning but I'm not sure is it gonna give me right results if I'm still on my period.Can someone help?Did u have a simular situation?